$$\log_9х\ =\ \frac{1}{2}$$  

(a)  

$$2^{\log_2\ х}\ =\ 4$$  

(a)  

$$\log_7\ х\ =\ 1$$  

(a)  

$$\log_3\ х\ =\ -2$$  

(a)  

$$\log_2\left(-х\right)\ =\ -3$$  

(a)  

$$\log_5\left(х-2\right)\ =\ 2$$  

(a)  

$$\lg_{ }\left(х+3\right)\ =\ \lg_{ }х$$  

(a)  

$$\lg_{ }х^2\ =\ 0$$  

(a)  

$$\log_2\left(2х+1\right)\ =\ 3$$  

(a)  

$$\lg_{1+x}2\ =\ 1$$  

(a)  

$$\lg_{ }\lg_{ }y\ =\ 0$$  

(a)